| Cover Page - shares | 3 Months Ended | |
| Apr. 30, 2020 | Jun. 01, 2020 | |
| Cover [Abstract] | ||
| Document Type | 10-Q/A | |
| Document Quarterly Report | true | |
| Document Period End Date | Apr. 30, 2020 | |
| Document Transition Report | false | |
| Entity File Number | 001-38464 | |
| Entity Registrant Name | Smartsheet Inc. | |
| Entity Incorporation, State or Country Code | WA | |
| Entity Tax Identification Number | 20-2954357 | |
| Entity Address, Address Line One | 10500 NE 8th Street, Suite 1300 | |
| Entity Address, City or Town | Bellevue, | |
| Entity Address, State or Province | WA | |
| Entity Address, Postal Zip Code | 98004 | |
| City Area Code | (844) | |
| Local Phone Number | 324-2360 | |
| Title of 12(b) Security | Class A common stock, no par value per share | |
| Trading Symbol | SMAR | |
| Security Exchange Name | NYSE | |
| Entity Current Reporting Status | Yes | |
| Entity Interactive Data Current | Yes | |
| Entity Filer Category | Large Accelerated Filer | |
| Entity Small Business | false | |
| Entity Emerging Growth Company | false | |
| Entity Shell Company | false | |
| Entity Common Stock Shares Outstanding (in shares) | 119,750,978 | |
| Amendment Description | Smartsheet Inc. (the “Company”) is filing this Amendment No. 1 to its quarterly report on Form 10-Q for the quarterly period ended April 30, 2020, as filed with the Securities and Exchange Commission on June 8, 2020 (the “Original Form 10-Q”), in order to correct the inadvertent omission of certain language in paragraph 4 of the certification of its Chief Executive Officer filed as Exhibit 31.1 and the certification of its Chief Financial Officer filed as Exhibit 31.2 to the Original Form 10-Q.This Amendment No. 1 should be read in conjunction with the Original Form 10-Q, which continues to speak as of the date of the Original Form 10-Q. Other than the filing of the corrected certifications mentioned above, this Amendment No. 1 does not modify or update the disclosures in the Original Form 10-Q in any way. Accordingly, this Amendment No. 1 does not reflect events occurring after the filing of the Original Form 10-Q or modify or update any related or other disclosures. | |
| Document Fiscal Year Focus | 2021 | |
| Amendment Flag | true | |
| Document Fiscal Period Focus | Q1 | |
| Current Fiscal Year End Date | --01-31 | |
| Entity Central Index Key | 0001366561 |
